Intel, Numonyx claim phase-change memory milestone

SAN FRANCISCOResearchers from Intel Corp. and its flash memory joint venture, Numonyx BV, have demonstrated the ability to stack multiple layers of phase-change memory (PCM) arrays within a single die, a breakthrough that could pave the way for PCM to one day displace multiple existing memory technologies in various applications, the companies said Wednesday (Oct. 28).

On a 64-megabit test chip, researchers say they were able to demonstrate a vertically integrated memory cell dubbed phase change memory and switch (PCMS). This cell is comprised of one PCM element layered with ovonic threshold switch (OTS) in a true cross-point array, according to the companies.

A paper describing the breakthrough is scheduled to be presented at the International Electron Devices Meeting (IEDM) in December.

According to Al Fazio, an Intel Fellow who directs the firm's memory technology development efforts, the ability to layer or stack arrays of PCMS should provide scalability to higher memory densities while maintaining the performance characteristics of PCM. Because it has been demonstrated to be stackable, the PCMS technology could one day displace NAND flash memory, which is not stackable, as well as other current memory technologies, Fazio said.

Fazio and Greg Atwood, senior technology Fellow at Numonyx, characterized the breakthrough as an early research milestone and suggested that a product based on PCMS is still years away. In order for PCMS to get to become a successful product it will have to prove its scalability and prove it has other "product-like capabilities," Fazio said. Eventually it would also need to compete against established memory technologies that have established economies of scale, he added.

Phase-change memory has long been viewed as an attractive long-term technology for non-volatile memory. But despite years of research, PCM in product form is barely out of the gate and has yet to show any signs of significant adoption. Many in the industry remain skeptical of PCM, voicing concerns over the cost-per bit, scalability of the technology and ability to meet write-speed requirements.

Solster,
I have written tomes about PCM. Those articles, which are
objective, are written and posted in the news section. Those
articles are mostly positive.
This is a blog; I can state my opinion here. In my opinion,
I am no big fan of PCM. PCM has gotten too much hype.
There is no evidence of any sales for PCM.
Intel has introduced the same part 20 (or more) times. We have published all
20 versions. Here's what I'm wondering: When will Phantom Change Memory
gain traction?

To Mark LePedus:
So, you are an editor. Conventional wisdom says an editor's job doesn't quite involve calling names to the subject of the articles they publish. Unless of course, their intent is to write in stone that their publication is really a tabloid. If you don't believe in the credibility of a press release or technology, do not report it. Someone else will.

My take:
PCM = Phase-change memory
Or is it this? Phantom-change memory or phony-change memory.
We keep writing about PCM, but it's still an R&D project.
Is anyone out there seeing PCM in volumes?
BAE Systems is said to have seen some samples.
Nokia wants it. Any OEMs gotten their hands on it?

Bri227, it will be interesting to see what their OTS actually is but I suspect it may just be a way of describing a diode. If you look at Samsung's 2005 IEDM paper (Baek et al.), they integrated thin film Ni-oxide and Ti-oxide to make selection diodes to their metal oxide switch for 3D memory. Unfortunately, these diodes had a maximum current drivability that was at least 3 orders of magnitude too small to deliver the current needed for resetting the material from low resistance to high resistance. PCM (at least in the literature) needs hundreds of microamps to reset which is not only a tall order for any 3D switch (i.e. diode) but also impacts the reset bandwidth (number of cells being reset per second).

Toom, if my read of this article is correct, they are using a thin film selection device instead of a stacked diode. They do not need a stacked diode. They are using a thin film device in place of a stacked diode.

Good idea Dylan. Turns out there aren't that many to choose from: (1) 3D versions of some switchable material such as PCM (Numonyx), Perovskite (Unity), Simple metal oxide (SanDisk, Toshiba), solid-state electrolyte (Axon) (2) NAND string in "horizontal direction" i.e. parallel with wafer plane, such as regular floating gate NAND (Samsung), TANOS (Samsung), SONOS with barrier engineering (Macronix), Dual-gate TFT SONOS (Schiltron) (3) NAND string in "vertical direction" such as BiCS (Toshiba) and VRAT (Samsung). Each approach has its advantages and disadvantages. The problem for the readers will be to discern the real state of affairs through all the hype that will grow and grow with the approaching NAND Flash brick wall.